Located at 13 01’N 042o 45’E, 1185 kms from the Eritrean capital, Asmara and 860 kms from the Ethiopian capital, Addis Abeba. the town has become an important port since it was purchased by the Rubattino Shipping Company for 8,100 Maria Teresa dollars from the local sultans on behalf of the Italian government in 1869. Assab was chosen for its strategic location near the straits of Bab el Mandeb, and the possibility that it could become an important trading station between Ethiopia and Arabia.

Assab now is a modern port, has seven commercial berths, one salt jetty with an oil refinery and three oil terminals built by the former Soviet Union. It used to be the main port serving Addis Ababa and therefore has more an Ethiopian than Eritrean feel to it.

The town is divided into three parts. Assab Seghir (small Assab) on the shoreline, Assab Kebir (big Assab) in the center of town, containing the port and the city center and nestling behind it is the rather ramshackle Campo Sudan, the former domain of Ethiopian residents. There are extensive salt flats around Assab. There are 30 islands in the Bay of Assab, which can be visited